Z370 Fan no full speed in DC mode

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   Hi All,

After some testing I've found the following on a Z370M-ITX/ac. All tests were done using UEFI. No SSD or HDD was installed and therefore no OS installed. Full setup spec's below.

With the 120mm case fan attached to CHA_FAN1/W_PUMP set to CHA_FAN1, DC Mode, Full Speed, the fan which is spec'd at 1500 RPM is reported to be running at 1300 RPM by the H/W monitor. I then measured the voltage on pin 2 of the connector which I expected to be 12 VDC and found it to be 8.16 VDC. Switching the Control mode to PWM the speed indication was 1710 RPM and the voltage on pin 2 measured 11.83 VDC. This is as expected as PWM mode requires the fan to have a constant 12 VDC supply and uses the control signal on pin 4 to adjust the speed. It also indicates that the fan is not introducing any excess loading, therefore the low voltage at Full Speed in DC Mode seems to indicate that there is a problem with the BIOS firmware which is currently ver 1.80.

I was wondering then if anyone else has observed this problem and if so whether either of the current BIOS updates, 1.90 and 2.10 have a fix for it. 

I also measured the voltage and RPM for the other settings in DC Mode, though unless there is some sort of speed feedback mechanism, I'm assuming the RPM is more likely to be fan specific. Following are all the results, Silent was not measured as the fan had stopped and I was concerned that it may still have voltage supplied to it and without movement it may overheat. Starting voltage for the 120mm fan is 5VDC.

Full Speed               8.6 VDC           1300 RPM
Performance Mode    5.75 VDC          976 RPM
Standard Mode        5.35 VDC          920 RPM
Silent Mode             Not Measured    0 RPM

I did try the Fan Tuning but the results as follows didn't make sense as when set to Monitor M/B the duty cycle for temp 2 is less than for temp 1. I'm guessing that in DC mode duty cycle actually means voltage output but I just can't be sure.

Temperature 1 - 40    Fan Duty for Temperature 1 - 65 %
Temperature 2 - 60    Fan Duty for Temperature 2 - 50 %
Temperature 3 - 75    Fan Duty for Temperature 3 - 90 %
Temperature 4 - 75    Fan Duty for Temperature 4 - 90 %
Critical temperature 75

I also tried manually entering a profile with all duty cyles set to 100%, temperature 1 to 30.0C, and monitoring CPU which was 40.0C but Fan 1 speed is still 1300 RPM. Following is the full profile.

Temperature 1 - 30    Fan Duty for Temperature 1 - 100 %
Temperature 2 - 40    Fan Duty for Temperature 2 - 100 %
Temperature 3 - 65    Fan Duty for Temperature 3 - 100 %
Temperature 4 - 75    Fan Duty for Temperature 4 - 100 %
Critical temperature 75

As the original 120mm fan supplied with the case was DOA, I've already bought a replacement to get the system up and running so I don't want to have to now replace it with a PWM fan to get around what is essentially a firmware fault. Slightly off topic, the 80mm fan that came with the case is also a DC controlled, 3 pin fan but as CHA_FAN2 appears only to work in PWM mode, as noted in other posts on this forum, the fan can only run at full speed. After the DOA 120mm fan experience I've also considered replacing the original 80mm fan with a PWM version but have been unable to source an 80mm x 14mm fan, which is the only size that fits in the case. 

Currently I've set the 120 mm fan back to PWM so it runs full speed (1700 RPM), the CPU fan to Full speed(2490 RPM) and have reconnected the 80mm fan to CHA_FAN2 to Full Speed (2100 RPM). M/B temp is 27.0C and CPU temp is 40.0C. With the air con on to warm the house, (it's winter here) I'm guessing the ambient temps around 22 - 24C.

The PC has been built for OS/networking lab tests. Fan tests used following config.

ASRock Z370M-ITX/ac mboard
UEIF version Z370M-ITX/ac P1.80 initially set to default factory settings
Intel i5 8400 CPU
Noctua NH-L9i CPU cooler
Cooler Master Elite 130 Mini-ITX Case
EVGA SuperNOVA 650W G1+ 80 PSU
Corsair Vengeance LPX 16GB (2x 8GB) DDR4 2666MHz Memory CMK16GX4M2A2666C16
- Set to auto so running at 2133 MHz
Vantec MRK-225S6-BK Dual Bay 2.5" SATA SSD/ HDD Removable Rack SATA III
No SSD or HDD currently installed so no OS running

The 120mm fan that came with the case was DOA and was replaced with
Jaycar YX2584 120mm fan with following spec
12VDC, 220mA, 1500RPM, 1.82m³/min, 3-wire tacho out, starting voltage is 5VDC

The 80mm fan that comes with the case was disconnected for the test.

Thanks all in advance

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NeedSleep Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 03 Jun 2018 Status: Offline Points: 3	Post Options Post Reply Quote NeedSleep Report Post Thanks(0) Quote Reply Topic: Z370 Fan no full speed in DC mode Posted: 06 Jun 2018 at 9:13am
	Hi All, After some testing I've found the following on a Z370M-ITX/ac. All tests were done using UEFI. No SSD or HDD was installed and therefore no OS installed. Full setup spec's below. With the 120mm case fan attached to CHA_FAN1/W_PUMP set to CHA_FAN1, DC Mode, Full Speed, the fan which is spec'd at 1500 RPM is reported to be running at 1300 RPM by the H/W monitor. I then measured the voltage on pin 2 of the connector which I expected to be 12 VDC and found it to be 8.16 VDC. Switching the Control mode to PWM the speed indication was 1710 RPM and the voltage on pin 2 measured 11.83 VDC. This is as expected as PWM mode requires the fan to have a constant 12 VDC supply and uses the control signal on pin 4 to adjust the speed. It also indicates that the fan is not introducing any excess loading, therefore the low voltage at Full Speed in DC Mode seems to indicate that there is a problem with the BIOS firmware which is currently ver 1.80. I was wondering then if anyone else has observed this problem and if so whether either of the current BIOS updates, 1.90 and 2.10 have a fix for it. I also measured the voltage and RPM for the other settings in DC Mode, though unless there is some sort of speed feedback mechanism, I'm assuming the RPM is more likely to be fan specific. Following are all the results, Silent was not measured as the fan had stopped and I was concerned that it may still have voltage supplied to it and without movement it may overheat. Starting voltage for the 120mm fan is 5VDC. Full Speed 8.6 VDC 1300 RPM Performance Mode 5.75 VDC 976 RPM Standard Mode 5.35 VDC 920 RPM Silent Mode Not Measured 0 RPM I did try the Fan Tuning but the results as follows didn't make sense as when set to Monitor M/B the duty cycle for temp 2 is less than for temp 1. I'm guessing that in DC mode duty cycle actually means voltage output but I just can't be sure. Temperature 1 - 40 Fan Duty for Temperature 1 - 65 % Temperature 2 - 60 Fan Duty for Temperature 2 - 50 % Temperature 3 - 75 Fan Duty for Temperature 3 - 90 % Temperature 4 - 75 Fan Duty for Temperature 4 - 90 % Critical temperature 75 I also tried manually entering a profile with all duty cyles set to 100%, temperature 1 to 30.0C, and monitoring CPU which was 40.0C but Fan 1 speed is still 1300 RPM. Following is the full profile. Temperature 1 - 30 Fan Duty for Temperature 1 - 100 % Temperature 2 - 40 Fan Duty for Temperature 2 - 100 % Temperature 3 - 65 Fan Duty for Temperature 3 - 100 % Temperature 4 - 75 Fan Duty for Temperature 4 - 100 % Critical temperature 75 As the original 120mm fan supplied with the case was DOA, I've already bought a replacement to get the system up and running so I don't want to have to now replace it with a PWM fan to get around what is essentially a firmware fault. Slightly off topic, the 80mm fan that came with the case is also a DC controlled, 3 pin fan but as CHA_FAN2 appears only to work in PWM mode, as noted in other posts on this forum, the fan can only run at full speed. After the DOA 120mm fan experience I've also considered replacing the original 80mm fan with a PWM version but have been unable to source an 80mm x 14mm fan, which is the only size that fits in the case. Currently I've set the 120 mm fan back to PWM so it runs full speed (1700 RPM), the CPU fan to Full speed(2490 RPM) and have reconnected the 80mm fan to CHA_FAN2 to Full Speed (2100 RPM). M/B temp is 27.0C and CPU temp is 40.0C. With the air con on to warm the house, (it's winter here) I'm guessing the ambient temps around 22 - 24C. The PC has been built for OS/networking lab tests. Fan tests used following config. ASRock Z370M-ITX/ac mboard UEIF version Z370M-ITX/ac P1.80 initially set to default factory settings Intel i5 8400 CPU Noctua NH-L9i CPU cooler Cooler Master Elite 130 Mini-ITX Case EVGA SuperNOVA 650W G1+ 80 PSU Corsair Vengeance LPX 16GB (2x 8GB) DDR4 2666MHz Memory CMK16GX4M2A2666C16 - Set to auto so running at 2133 MHz Vantec MRK-225S6-BK Dual Bay 2.5" SATA SSD/ HDD Removable Rack SATA III No SSD or HDD currently installed so no OS running The 120mm fan that came with the case was DOA and was replaced with Jaycar YX2584 120mm fan with following spec 12VDC, 220mA, 1500RPM, 1.82m³/min, 3-wire tacho out, starting voltage is 5VDC The 80mm fan that comes with the case was disconnected for the test. Thanks all in advance